MAX3232 Circuit + GPS Current Draw

[daneloctober]

Hello!

I'm having a little trouble here. So I used a TL431 for powering a MAX3232 circuit and a GPS module which are both rated at 3.3V. Here's the link for the GPS module datasheet:
https://www.rfsolutions.co.uk/acatalog/DS-GPS610F-2.pdf

This is the schematic:


I used 15 ohms so I can draw about 100mA.

I expected the gps to draw about 36mA, and the MAX3232 circuit to draw about 50mA+, but then this happened:


I don't have any current measuring tools right now, can someone give me like an estimate or data from past experience when you worked with the MAX3232?... I was thinking of using two 1/4W 30Ohm resistors but maybe that would still not be enough so I really need to know the MAX3232 circuit's current draw...

THANK YOU VERY MUCH!

 

[tpetar]

GPS module and MAX3232 both can work on 3,3V and 5V. GPS module uses 23-36mA during tracking, and typical 70mA in enchanced-mode acquisition.

MAX3232 datasheet
https://pdfserv.maximintegrated.com/en/ds/MAX3222-MAX3241.pdf


I didnt catch what you trying to do with TL431, you just need to give supply to devices (3,3V in your case). Both devices support up to 5V and Li-Ion/Li-Po batteries can go up to 4,21V. This means you can use battery without any special regulation of voltage.


Best regards,
Peter

 

[daneloctober]

GPS module and MAX3232 both can work on 3,3V and 5V. GPS module uses 23-36mA during tracking, and typical 70mA in enchanced-mode acquisition.

If you look at the pin out description, Vcc is 3.3V. I'm not sure why it's stated earlier in the datasheet that input voltage is 3.3/5. But to be safe, I just used 3.3V.

I didnt catch what you trying to do with TL431, you just need to give supply to devices (3,3V in your case).

Yes, of course I've looked at the datasheet. But I believe the current consumption stated there is only for the MAX3232 IC, not the whole circuit with the capacitors and stuff. I'm just asking if anybody has ever used the MAX3232 before and if they were able to determine the current consumption of the WHOLE circuit: IC + Caps. Not just the IC. Notice I always say "MAX3232 circuit" in my inquiry, and not just MAX3232.

Also, TL431 makes for a good low voltage regulator. That's what I used it for. There's no problem with it. I just need to know if replacing the 15 ohm resistor in the schematic i posted with a resistor with a 1/2W power rating would solve the problem, or would I need something higher...